/*
 *                               POK header
 *
 * The following file is a part of the POK project. Any modification should
 * be made according to the POK licence. You CANNOT use this file or a part
 * of a file for your own project.
 *
 * For more information on the POK licence, please see our LICENCE FILE
 *
 * Please follow the coding guidelines described in doc/CODING_GUIDELINES
 *
 *                                      Copyright (c) 2007-2021 POK team
 */

/* e_remainderf.c -- float version of e_remainder.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#ifdef POK_NEEDS_LIBMATH

#include "math_private.h"
#include <libm.h>

static const float zero = 0.0;

float __ieee754_remainderf(float x, float p) {
  int32_t hx, hp;
  uint32_t sx;
  float p_half;

  GET_FLOAT_WORD(hx, x);
  GET_FLOAT_WORD(hp, p);
  sx = hx & 0x80000000;
  hp &= 0x7fffffff;
  hx &= 0x7fffffff;

  /* purge off exception values */
  if (hp == 0)
    return (x * p) / (x * p); /* p = 0 */
  if ((hx >= 0x7f800000) ||   /* x not finite */
      ((hp > 0x7f800000)))    /* p is NaN */
    return (x * p) / (x * p);

  if (hp <= 0x7effffff)
    x = __ieee754_fmodf(x, p + p); /* now x < 2p */
  if ((hx - hp) == 0)
    return zero * x;
  x = fabsf(x);
  p = fabsf(p);
  if (hp < 0x01000000) {
    if (x + x > p) {
      x -= p;
      if (x + x >= p)
        x -= p;
    }
  } else {
    p_half = (float)0.5 * p;
    if (x > p_half) {
      x -= p;
      if (x >= p_half)
        x -= p;
    }
  }
  GET_FLOAT_WORD(hx, x);
  SET_FLOAT_WORD(x, hx ^ sx);
  return x;
}
#endif
